package com.lcz.audioplayer;

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.RelativeLayout;
import android.widget.ScrollView;
import android.widget.Scroller;

/** 
 * 自定义可以滑动的RelativeLayout, 类似于IOS的滑动删除页面效果，当我们要使用 
 * 此功能的时候，需要将该Activity的顶层布局设置为SlitherFinishLayout， 
 * 然后需要调用setTouchView()方法来设置需要滑动的View
 */  
public class SlitherFinishLayout extends RelativeLayout implements OnTouchListener {

    /** 
     * SlitherFinishLayout布局的父布局 
     */  
    private ViewGroup mParentView;
    /** 
     * 处理滑动逻辑的View 
     */  
    private View touchView;
    /** 
     * 滑动的最小距离 
     */  
    private int mTouchSlop;  
    /** 
     * 按下点的X坐标 
     */  
    private int downX;  
    /** 
     * 按下点的Y坐标 
     */  
    private int downY;  
    /** 
     * 临时存储X坐标 
     */  
    private int tempX;  
    /** 
     * 滑动类 
     */  
    private Scroller mScroller;
    /** 
     * SlitherFinishLayout的宽度 
     */  
    private int viewWidth;  
    /** 
     * 记录是否正在滑动 
     */  
    private boolean isSlither;  
      
    private OnSlitherFinishListener onSlitherFinishListener;  
    private boolean isFinish;  
      
  
    public SlitherFinishLayout(Context context, AttributeSet attrs) {
        this(context, attrs, 0);  
    }  


    public SlitherFinishLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
        mScroller = new Scroller(context);
    }  


    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {  
        super.onLayout(changed, l, t, r, b);  
        if (changed) {  
            // 获取SlitherFinishLayout所在布局的父布局  
            mParentView = (ViewGroup) this.getParent();
            viewWidth = this.getWidth();  
        }  
    }  


    /** 
     * 设置OnSlitherFinishListener, 在onSlitherFinish()方法中finish Activity 
     * @param onSlitherFinishListener           listener
     */  
    public void setOnSlitherFinishListener(OnSlitherFinishListener onSlitherFinishListener) {
        this.onSlitherFinishListener = onSlitherFinishListener;  
    }

  
    /** 
     * 设置Touch的View 
     * @param touchView                 触摸view
     */  
    public void setTouchView(View touchView) {
        this.touchView = touchView;  
        touchView.setOnTouchListener(this);  
    }

  
    /** 
     * 滚动出界面 
     */  
    private void scrollRight() {  
        final int delta = (viewWidth + mParentView.getScrollX());  
        // 调用startScroll方法来设置一些滚动的参数，我们在computeScroll()方法中调用scrollTo来滚动item  
        mScroller.startScroll(mParentView.getScrollX(), 0, -delta + 1, 0, Math.abs(delta));
        postInvalidate();  
    }

  
    /** 
     * 滚动到起始位置 
     */  
    private void scrollOrigin() {  
        int delta = mParentView.getScrollX();  
        mScroller.startScroll(mParentView.getScrollX(), 0, -delta, 0, Math.abs(delta));
        postInvalidate();  
    }

  
    /** 
     * touch的View是否是AbsListView， 例如ListView, GridView等其子类 
     * @return
     */  
    private boolean isTouchOnAbsListView() {
        if(touchView instanceof AbsListView){
            return true;
        }else {
            return false;
        }
    }

  
    /** 
     * touch的view是否是ScrollView或者其子类 
     * @return
     */  
    private boolean isTouchOnScrollView() {
        if(touchView instanceof ScrollView){
            return true;
        }else {
            return false;
        }
    }


    @Override
    public boolean onTouch(View v, MotionEvent event) {
        switch (event.getAction()) {  
            case MotionEvent.ACTION_DOWN:
                downX = tempX = (int) event.getRawX();
                downY = (int) event.getRawY();
                break;
            case MotionEvent.ACTION_MOVE:
                int moveX = (int) event.getRawX();
                int deltaX = tempX - moveX;
                tempX = moveX;
                if (Math.abs(moveX - downX) > mTouchSlop && Math.abs((int) event.getRawY() - downY) < mTouchSlop) {
                    isSlither = true;
                    // 若touchView是AbsListView，
                    // 则当手指滑动，取消item的点击事件，不然我们滑动也伴随着item点击事件的发生
                    if (isTouchOnAbsListView()) {
                        MotionEvent cancelEvent = MotionEvent.obtain(event);
                        cancelEvent.setAction(MotionEvent.ACTION_CANCEL
                                | (event.getActionIndex() << MotionEvent.ACTION_POINTER_INDEX_SHIFT));
                        v.onTouchEvent(cancelEvent);
                    }
                }
                if (moveX - downX >= 0 && isSlither) {
                    mParentView.scrollBy(deltaX, 0);
                    // 屏蔽在滑动过程中ListView ScrollView等自己的滑动事件
                    if (isTouchOnScrollView() || isTouchOnAbsListView()) {
                        return true;
                    }
                }
                break;
            case MotionEvent.ACTION_UP:
                isSlither = false;
                if (mParentView.getScrollX() <= - viewWidth / 2) {
                    //当X轴滑动位移大于或者等于1/2屏幕宽度时，滚动出界面
                    isFinish = true;
                    scrollRight();
                } else {
                    //当X轴滑动位移小于1/2屏幕宽度时，滚动到起始位置
                    scrollOrigin();
                    isFinish = false;
                }
                break;
            default:
                break;
        }
        // 假如touch的view是AbsListView或者ScrollView 我们处理完上面自己的逻辑之后  
        // 再交给AbsListView, ScrollView自己处理其自己的逻辑  
        if (isTouchOnScrollView() || isTouchOnAbsListView()) {
            return v.onTouchEvent(event);  
        }
        // 其他的情况直接返回true  
        return true;  
    }  


    @Override
    public void computeScroll() {  
        // 调用startScroll的时候scroller.computeScrollOffset()返回true，  
        if (mScroller.computeScrollOffset()) {  
            mParentView.scrollTo(mScroller.getCurrX(), mScroller.getCurrY());  
            postInvalidate();
            if (mScroller.isFinished()) {
                if (onSlitherFinishListener != null && isFinish) {  
                    onSlitherFinishListener.onSlitherFinish();  
                }  
            }  
        }  
    }  

  
    public interface OnSlitherFinishListener {
        /**
         * 在滑动结束后调用
         */
        void onSlitherFinish();
    }  


}  

